Collection Query Snapshot changes and just snapshot changes are firing with mixed results

[jimmykane]

Version info

Angular: 7.1.3

Firebase: 5.7.0

**AngularFire:**5.1.1

Other (e.g. Ionic/Cordova, Node, browser, operating system):

How to reproduce these conditions

Failing test unit, Plunkr, or JSFiddle demonstrating the problem

No plunker possible

Steps to set up and reproduce

1. In my service I have a call to a collection query by multiple where clauses and return back a single observable.

public getStreams(eventID: string, activityID: string, types: string[]): Observable<StreamInterface[]> {
    return combineLatest.apply(this, types.map((type) => {
      return this.afs
        .collection('events')
        .doc(eventID)
        .collection('activities')
        .doc(activityID)
        .collection('streams', ref => ref.where('type', '==', type))
        .snapshotChanges()
        .pipe(map((streamSnapshots) => { // @todo should be reduce
          return this.processStreamSnapshots(streamSnapshots)[0] // Get the first element of the return
        }))                                                      // since the return with equality on the query should only fetch one afaik in my model
    })).pipe(map((streams: StreamInterface[]) => {
      return streams.filter((stream) => !!stream)
    }))

2. Then I have some other call that fetches everything from that collection

public getAllStreams(eventID: string, activityID: string): Observable<StreamInterface[]> {
    return this.afs
      .collection('events')
      .doc(eventID)
      .collection('activities')
      .doc(activityID)
      .collection('streams')
      .snapshotChanges()
      .pipe(map((streamSnapshots) => {
        debugger;
        return this.processStreamSnapshots(streamSnapshots);
      }))
  }

I am calling and subscribing first on the multiple where query of my service eg:

this.streamsSubscriptions.push(this.eventService.getStreams(this.event.getID(), activity.getID(), [DataLatitudeDegrees.type, DataLongitudeDegrees.type])

Than at some point later I subscribe also to the "all" list

this.eventService.getAllStreams(this.event.getID(), activity.getID());

However the 'all' call gets triggered 2 times.
One it returns the results of the:

this.streamsSubscriptions.push(this.eventService.getStreams(this.event.getID(), activity.getID(), [DataLatitudeDegrees.type, DataLongitudeDegrees.type])

... which in my logic is an array of 2

And the second time it returns as expected all the results. (Array of lets say 20)

What am I missing or is this a bug

I would expect only one call with just all the results

Sample data and security rules

No data

Debug output

** Errors in the JavaScript console **

** Output from firebase.database().enableLogging(true); **

** Screenshots **

Expected behavior

See description

Actual behavior

See description

[jek-bao-choo]

same here. experiencing this problem.

[phihochzwei]

We are facing the exact same problem here. Anyone a solution for this?

[jimmykane]

See

public getAllStreams(user: User, eventID: string, activityID: string): Observable<StreamInterface[]> {
    return this.afs
      .collection('users')
      .doc(user.uid)
      .collection('events')
      .doc(eventID)
      .collection('activities')
      .doc(activityID)
      .collection('streams')
      .get() // @todo replace with snapshot changes I suppose when @https://github.com/angular/angularfire2/issues/1552 is fixed
      .pipe(map((querySnapshot) => {
        return querySnapshot.docs.map(queryDocumentSnapshot => this.processStreamQueryDocumentSnapshot(queryDocumentSnapshot))
      }))
  }

The comment there on the above block.

In short use get to ensure

[jamesdaniels]

I'm not exactly clear what this issue is? Does it remain or is this outdated. Closing for now but will reopen if still exists.